Control devices of this type are already known. In the known control devices, the cams which control the feed movement and the limit stop are each newly located during adjustment of the machine. This setting of the cams is time consuming and increases the expense of the entire working time on the machine, in particular if a small number of pieces are to be worked, which is particularly the case in machines working on large workpieces, in particular large gears.
Therefore, the basic purpose of the invention is to provide a device wherein the setting up of the machine is simplified and the time needed for this is shortened. The basic purpose of the invention is attained with a control device wherein the final position of the carriage can be driven from a control switch and which faces the workpiece, is determined by two cam carriages, of which the first cam carriage can be positioned with a rough or coarse adjustment relative to the machine frame and the second cam carriage which has a stop surface thereon can be finely adjusted relative to the first cam carriage, and wherein the cam carriages carry the cams which control the feed at the end of the carriage path which faces the workpiece. This device has not only advantages with respect to adjusting the cams and the end positions, but hobbing machines can be simply and quickly set for both a method having a longitudinal feed and also for plunge cutting.
Particularly advantageous is a development wherein the end position is controlled by an electric motion pickup device, for example by means of an inductive motion pickup device which controls the feed speed to zero and which is driven into engagement with the stop surface, because through this the end position can be precisely controlled for protection of the machine. Inductive motion pickup devices are common in commerce and are sold for example by the Firm Novotechnik KG, Offerdinger & Co. 7304 Ruit near Stuttgart, Federal Republic of Germany, under the name Linotast.
The accomplishment of a rough of coarse adjustment is attained in a simple manner by providing a screw spindle and a spindle nut while a simple and exact adjustment of the limit stop surface can take place in a favorable manner by providing a micrometer screw.
The path of the carriage, in particular the cutting carriage can be adjusted to an optimum position by providing a further cam on the machine column or carrier for the cam carriage or a corresponding part, which further cam can be adjusted and secured on the path of the carriage, for example cutting carriage. The cam is the only cam which must be set for the feed movement.
In order to be able to cut on hobbing machines cluster gears having gears with differing diameters or in order to be able to carry out a multi-cut method or in order to be able to carry out corresponding operations on different tool machines, the first cam carriage can be switched over relative to the spindle nut to at least two positions and an easy handling is assured by making the path of adjustment of the first cam carriage adjustable relative to the spindle nut with a stop device and by providing a micrometer screw for adjusting the stop devices.
The invention has the further purpose of providing an economical copying device for a small copying stroke over a large field of adjustment and which is formed of the entire downfeed stroke and the entire longitudinal path.
This purpose is attained by providing a second electric motion pickup device, for example an inductive motion pickup device, which engages a template or the like, which has the same or proportional characteristic line as the first electric motion pickup device and which trails the second motion pickup device which acts as its transmitter. Such a device unifies the advantage of being able to set the machine simply and shortening the time needed therefor, in particular also the advantage that the end position of the carriage is controlled carefully and very exactly with the advantage that in spite of the large field of adjustment a simple copying device which is suitable for a relatively small copying path can be provided.
Further objects and purposes as well as advantages and characteristics of the invention will become clear from the following description.